1. Field
The present disclosure relates generally to methods and apparatus for testing of communications systems, and more particularly to apparatus and methods for testing a multicarrier wireless system using a modulation error ratio.
2. Background
Multicarrier wireless systems include Forward Link Only (FLO), which is a digital wireless technology that has been developed by an industry-led group of wireless providers. The FLO technology was designed, in part, for a mobile multimedia environment and exhibits performance characteristics suited for cellular handset use. FLO technology uses orthogonal frequency division multiplexing (OFDM) and advances in coding and interleaving to achieve high-quality reception, both for real-time content streaming and other data services. FLO technology can provide robust mobile performance and high capacity without compromising power consumption. The technology also reduces the network cost of delivering multimedia content by dramatically decreasing the number of transmitters that need to be deployed.
FLO wireless systems may be used, in particular, to broadcast real time audio and video signals, apart from non-real time services to mobile users. Broadcast transmission is typically carried out using tall and high power transmitters or to employ repeater/transmitters to ensure wide coverage or extend coverage over a given geographical area. Given the nature of FLO broadcasts, which support multimedia data, it is important that the transmitted signal and, hence, the transmitter or repeater/transmitter, provide good performance over a range of channel conditions. Accordingly, the ability to accurately, yet efficiently, test transmitter or repeater/transmitter performance is desirable.
Known approaches for testing transmitter performance include an effective signal to noise ratio (SNR) approach, which provides a good measure of FLO device performance under a range of channel conditions. For repeater/transmitters, however, using an effective SNR approach is not appropriate, since the performance of the repeater/transmitter in such a method is determined by implementation noise instead of channel noise.